How to implement single logout using okta as IDP?

问题

In Okta developer account I have enabled the SAML Single Logout and get Identity Provider Single Logout URL. I have created following logout request using NameID and SessionIndex obtained from SAML response that we get during single sign-on process.

Logout Request :

<?xml version="1.0" encoding="UTF-8"?>
<samlp:LogoutRequest xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" Destination="https://dev-6#####.oktapreview.com/app/nepasoftdev660864_spdemo_1/exk606bnr5BZOBF7z0h7/slo/saml" ID="_b2be5dbd-928a-4554-a879-25a179e36ee2" IssueInstant="2016-03-25T10:20:47Z" Version="2.0">
   <saml:Issuer xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion">http://192.###.###.##/spdemo</saml:Issuer>
   <saml:NameID xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion" Format="urn:oasis:names:tc:SAML:2.0:nameid-format:transient">ramesh.shrestha@nepasoft.com</saml:NameID>
   <samlp:SessionIndex>id1458901238038.94596883</samlp:SessionIndex>
</samlp:LogoutRequest>

I am getting the following Logout Response with status code RequestDenied

<?xml version="1.0" encoding="UTF-8"?>
<saml2p:LogoutResponse xmlns:saml2p="urn:oasis:names:tc:SAML:2.0:protocol" Destination="http://localhost:10262/Logout.aspx" ID="id1846510753301801884197562" InResponseTo="_b2be5dbd-928a-4554-a879-25a179e36ee2" IssueInstant="2016-03-25T10:22:40.389Z" Version="2.0">
   <saml2:Issuer xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion" Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">http://192.###.###.##/spdemo</saml2:Issuer>
   <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
      <ds:SignedInfo>
         <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
         <ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
         <ds:Reference URI="#id1846510753301801884197562">
            <ds:Transforms>
               <ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
               <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
            </ds:Transforms>
            <ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
            <ds:DigestValue>LQwvto+ERXvrQRUB7LOUUznSXII=</ds:DigestValue>
         </ds:Reference>
      </ds:SignedInfo>
      <ds:SignatureValue>P+T1K.....ZYvCw==</ds:SignatureValue>
      <ds:KeyInfo>
         <ds:X509Data>
            <ds:X509Certificate>MIID.....7zK0rH</ds:X509Certificate>
         </ds:X509Data>
      </ds:KeyInfo>
   </ds:Signature>
   <saml2p:Status>
      <saml2p:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:RequestDenied" />
   </saml2p:Status>
</saml2p:LogoutResponse>

Why might be the reason for getting RequestDenied status? Did i missed something on logout request or misconfigured during enabling single logout in Okta?

Thanks in advanced.

回答1:

You also need to sign the LogoutRequest so you would need to include a Signature element (similar to what you are getting back in the LogoutResponse).

That said, I'm running into the same issue you are. I have signed my LogoutRequest but am still getting a LogoutResponse with status RequestDenied.

I did find this thread (https://support.okta.com/help/answers?id=906F0000000I07YIAS) on Okta's support page which indicates that the HTTP-Redirect binding is not supported for logout so you may need to you HTTP-Post. I've not tried that yet.

来源：https://stackoverflow.com/questions/36218298/how-to-implement-single-logout-using-okta-as-idp